63 lines
1.7 KiB
JavaScript
63 lines
1.7 KiB
JavaScript
System.register(['react'], (function (exports) {
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'use strict';
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var ReactExports;
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return {
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setters: [function (module) {
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ReactExports = module.default;
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}],
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execute: (function () {
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exports('useShallow', useShallow);
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function shallow(objA, objB) {
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if (Object.is(objA, objB)) {
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return true;
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}
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if (typeof objA !== "object" || objA === null || typeof objB !== "object" || objB === null) {
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return false;
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}
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if (objA instanceof Map && objB instanceof Map) {
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if (objA.size !== objB.size)
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return false;
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for (const [key, value] of objA) {
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if (!Object.is(value, objB.get(key))) {
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return false;
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}
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}
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return true;
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}
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if (objA instanceof Set && objB instanceof Set) {
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if (objA.size !== objB.size)
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return false;
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for (const value of objA) {
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if (!objB.has(value)) {
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return false;
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}
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}
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return true;
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}
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const keysA = Object.keys(objA);
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if (keysA.length !== Object.keys(objB).length) {
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return false;
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}
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for (let i = 0; i < keysA.length; i++) {
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if (!Object.prototype.hasOwnProperty.call(objB, keysA[i]) || !Object.is(objA[keysA[i]], objB[keysA[i]])) {
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return false;
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}
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}
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return true;
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}
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const { useRef } = ReactExports;
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function useShallow(selector) {
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const prev = useRef();
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return (state) => {
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const next = selector(state);
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return shallow(prev.current, next) ? prev.current : prev.current = next;
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};
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}
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})
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};
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}));
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